The invention concerns a guide apparatus for instruments, in particular orthodontal and dental instruments for producing cavities such as recesses and bores--for implants in bone tissue.
Bores and recesses--in particular slots--which are to be produced by drilling or milling are required for fitting implants in surgery, orthopedics or jaw and oral surgery. In most cases such bores and recesses are produced by a procedure whereby a drilling template is fitted on to the location to be provided with the cavity, the template acting as a guide means to permit the drilling operation to be effected with a relatively high degree of accuracy. The production of a slot is substantially more difficult as the transverse movement of the drill or milling tool has to be implemented by hand and this therefore presupposes a considerable degree of skill on the part of the operator. Abutments which are mounted to the drilling machine or to the drilling head are used to maintain the precise depth for such slots.
In all operations in which bores or slots have to be operatively produced in bone tissue, the influence of the operator skill remains a high-risk factor involved in such procedures, even when the abovementioned drilling templates which in most cases are produced on the basis of X-ray images help to improve the level of accuracy.
In regard to all known apparatuses and templates in the area of operational technology, there is no possibility of producing bores or slots with a high degree of precision by an automatic or semi-automatic procedure. Not least for that reason very long operating times have to be accepted and high levels of cost tolerated.
Accordingly, it is a principle object of the invention to provide a guide apparatus of the kind set forth above, which permits precise production of the cavities--in particular slots--, which shortens operating times and which reduces costs.
The foregoing object is achieved by way of the present invention wherein a guide apparatus for instruments, in particular for orthodontal and dental instruments for producing cavities such as recesses and bores for implants in bone tissue, characterised in that an instrument holder which receives the instrument is arranged at the guide apparatus which can be fixed at a fixed point, the instrument holder being displaceable in at least two mutually crossing directions and being rotatable about at least one pivot axis.
In accordance with the invention an instrument holder which receives the instrument is arranged at a guide apparatus--which can be fixed at a fixed point--displaceably in at least two mutually crossing directions and rotatably about at least one pivot axis. In that respect, it has been found advantageous if the instrument holder is mounted displaceably in three co-ordinate directions and/or rotatably about the pivot axis through an angle of more than 90.degree.--preferably 360.degree.. It is particularly advantageous for the instrument holder also to be arranged pivotably about a second pivot axis which crosses the first pivot axis.
The features according to the invention therefore provide a guide apparatus having an instrument holder for the drilling and milling head, which is to be set in linearly accurately fashion in more than two axes and which is also rotatable and inclinable with a high degree of precision.
In accordance with a further feature of the invention the instrument holder which is mounted to a working head of the guide apparatus is adapted to be displaceable transversely with respect to the longitudinal axis of the guide apparatus on a carriage or slider and is adapted to be lifted with the carriage or slider. It is preferably disposed laterally of the working head on a bar or the like strip of material which projects beyond same.
In accordance with the invention, a respective rotary handle for linear displacement by hand is provided for the path of movement of the instrument holder, which crosses the longitudinal axis, and for the stroke movement of the working head; each of the rotary handles may be replaced by an electrical, pneumatic or hydraulic drive.
It has also proven to be desirable for the working head to be rotatably connected by a pivot pin to a carrier tongue of an intermediate portion of the guide apparatus, which portion at the other end displaceably mounts to a carriage or slider connected to the fixed point. By virtue of the carriage or slider the intermediate portion with the working head is reversible parallel to the longitudinal axis of the guide apparatus.
At a spacing relative to that pivot pin the carrier tongue can be fixed to the intermediate portion rotatably about the longitudinal axis--that is to say at a right angle to the axis of the pivot pin. For that purpose the carrier tongue projects from a rotary disk which is connected to a shaft and which bears rotatably against a disk-like bearing surface of the intermediate portion. The rotary disk which is preferably rotatable through an angle of 360.degree. is connected by way of the shaft to a setting knob by which it can be fixed in a desired rotational position.
Both the front carriage or slider on the working head, which is to be displaced transversely with respect to the longitudinal axis and which can also be lifted, and also the rear carriage or slider which in accordance with the invention is connected to the intermediate portion by way of an adjusting spindle and whose path of movement extends parallel to the longitudinal axis of the guide apparatus are each provided with a rotary handle for actuation thereof. If there is a wish to change over from manual operation to automatic operation, those rotary handles in accordance with the invention are themselves in the form of motors or drive means or are replaced by such.
Thus it is in accordance with the invention that the working head is designed to be displaceable in a plurality of axes by the carriages or sliders having a fine screwthread, with electrical, electronic, pneumatic or hydraulic drives. In that respect, on the one hand electrical stepping motors or electronic magnetic or dc motors are preferred as drives. On the other hand pneumatic drives are to be operated in particular with compressed air or compressed nitrogen as the drive medium; water or oil are preferred as the drive medium for hydraulic drives; in accordance with a further feature of the invention, they are to be passed in a closed circuit.
In accordance with the invention, preferably at least one display device for the setting data is associated with the actuating member or members or rotary handle or handles for the carriage or carriages and/or the rotary axis, for precise monitoring of the movements involved.
In accordance with further features of the invention, measurement scales can be provided on the carriage or carriages or the rotary axis or axes, and at least one electromechanical read-off system is possibly associated with the measurement scales.
It can also be of importance in regard to the invention that the entire installation as described can be set and adjusted by way of a computer, preferably by way of an X-ray picture which is fed into the computer; by virtue of the X-ray picture the installation can even be automatically set and adjusted.
If it is assumed that any drilling or milling unit which can be used in surgery or jaw or oral surgery can be mounted on the motion unit or the working head which is controlled in a plurality of axes, the result then is a system which impressively attains the object set by the inventor.